Correlation, Florpyrauxifen, Rice herbicides, Principal component analysis, Weed control efficiency
Aquatic weeds often pose a serious threat to wetland rice production. An experiment was conducted at All India Coordinated Research Project (AICRP) on Weed Management, Kerala Agricultural University, India to evaluate the performance of post-emergence herbicides for the management of two broad-leaf aquatic weeds Limnocharis flava and Monochoria vaginalis during the rainy (Kharif) and winter (Rabi) seasons of 2022. The experiment was laid out with eleven treatments, consisting of recommended dose of 2,4-D-sodium salt, penoxsulam + butachlor, penoxsulam + pendimethalin, metsulfuron-methyl + chlorimuron-ethyl, florpyrauxifen-benzyl, bispyribac-sodium, penoxsulam + cyhalofop-butyl, carfentrazone-ethyl, pretilachlor + pyrazosulfuron-ethyl, hand weeding at 20 and 40 days after transplanting and un-weeded control. Weed management treatments had significant effect on the weed density, weed dry matter, and crop yield. Post-emergence application of 2,4-D-sodium salt and florpyrauxifen-benzyl as well as hand weeding twice resulted in total control of both Limnocharis falva and Monochoria vaginalis. All the herbicides applied along with a wetting agent recorded 70-100% weed control efficiency. 2,4-D Na salt and hand weeding twice produced the highest grain yield and straw yields followed by florpyrauxifen-benzyl. Season-long weed competition caused 68% reduction in the grain yield in un-weeded plot. The findings provide an array of herbicides which can be included in herbicide rotation for broad-spectrum weed control, especially Limnocharis and Monochoria in wetland rice fields.